Two levels, one a Bungie port (What goes up, must come down) and one a port from the M1 Netwired collection (Dementia). The original level works better... I wish the water were deeper.
Six levels. Designed for 2-4 players. We found all six to be really enjoyable in three-person games. These games really favor the accurate shooter over the insdiscriminate aim-the-spanker-in-the-general-direction type.